Not necessary for LHD cars. The reason that the cars are so easily stolen when RHD is that the interior alarm sensors do not always pick up movement on the drivers side as the sensors only cover a limited amount of the right-hand side of the car, allowing a theif to smash the driver's window, reach down to the OBD port and reprogram a key as the OBD port does not sleep while the car is locked. In BMW's wisdom they only thought to provide sensors that cover the driver's side of the cars when LHD, a real oversight as someone at BMW obviously forgot that they sell LHD versions too.

You'd probably find that if any of you LHD guys smashed your passenger side window that the alarm may not sound but that's not a big deal when it comes to theft as a theif would set the alarm off the moment they reached anywhere near the centre console.

The CAS module update disables the comfort access, or parts of it, and sends the OBD port to sleep when the car is locked and without a key in the ignition. For example with this update the car will not let you drop the windows when holding the key in the lock however, it will still let you drop them via the remote.

The way I see it is that theis must have originally start as a tip of from inside BMW, either that or a thief got lucky a couple times smashing driver's windows on RHD cars and dreamt the plan up.